Gripping apparatus for handling elongated objects



June 5, 1956 A. w. PETE-RSON GRIPPING APPARATUS FOR HANDLING EILONGATEDOBJECTS Filed June 6, 1952 United States Patent GRIPPING APPARATUS FORHANDLING ELONGATED OBJECTS Alden W. Peterson, Lorain, Ohio, assignor toUnited States Steel Corporation, a corporation of New Jersey ApplicationJune 6, 1952, Serial No. 292,135

4 Claims. (Cl. 294-113) The present invention relates to apparatus forhandling elongated objects and more patricularly to a gripper mechanismespecially suitable for facilitating the grasping and lifting ofelongated objects.

The apparatus of the present invention is especially suited for handlingrefractory tuyeres of the type used in Bessemer converters, and is,therefore, described in connection with the handling of such tuyereswhile being installed in the bottoms of Bessemer converters. It is to beunderstood, however, that the invention is not limited to suchapplication.

' The tuyeres used in Bessemer converters are made of refractorymaterial formed in the shape of elongated cyinders having shoulders atone end. The tuyeres which are imbedded in refractory material coveringthe bottom of the converter extend upwardly when in operating positionto conduct air into the converter. Through use, the bottom refractoryand the tuyeres of a Bessemer converter burn partly away and must bereplaced. The replacement tuyeres are pushed up through the openings inthe bottom plate of the converter and are fastened in place from belowwith bar clamps while brick and refractory mud are filled in around themto repair the bottom. During installation, the replacement tuyeres arepushed up from below through the openings in the converter bottom singlyby workmen positioned underneath the converter bottom. As each tuyereispushed up through its opening, it is grasped by a workman standing aboveon the bottom plate and raised until the tuyere shoulder abuts thesocket edge of the opening. Then the workman above holds the tuyere inposition until the workmen below afiix the clamp bar in position.

Prior to my invention, the workman above lifted the tuyere with hishands and then held it in raised position between his legs, using bothlegs and arms to hold the tuyere steady while it was being fastenedbelow.

In some plants the workmen above used a pair of tongs which wereprovided with curved jaw faces shaped to grip the tuyere. These tongswere manipulated by pushing the handles toward one another to cause thecurved jaw faces to close on the tuyere. The gripping force exerted bythis tool was approximately equal to the force exerted by the horizontalarm squeeze at the handles. When using this tool, it was necessary forthe workman to simultaneously squeeze on the handles while exerting alifting force to support the tuyere and to hold the shoulder up againstthe socket. This was a difiicult task, with arms at chest height,lifting and squeezing, with no appreciable mechanical advantage. Thedanger of the tuyere getting loose and slipping constituted aconsiderable safety hazard to the men working below the converterbottom.

It is, accordingly, an object of my invention to provide a pivotedlifting clamp for handling an elongated object which, when fitted aroundthe object, exerts a positive gripping force when lifted.

It is a further object of my invention to provide clamping apparatuswhich may be used by a workman for lifting and supporting an elongatedobject in a vertical plane with a minimum of physical exertion.

These and other objects will become more apparent after referring to thefollowing specification and attached drawings, in which:

Figure 1 is a plan of the tool of my invention in position for grippinga tuyere or other elongated object;

Figure 2 is a side elevational view of Figure 1;

Figure 3 is a sectional view taken on the line III-III of Figure 1;

Figure 4 is an enlarged detail side elevational view showing the limitof movement of the pivotal members of my tool in open non-grippingposition; and

Figure 5 is a view similar to Figure 4 showing the limit of movement ofthe pivotal members in closed gripping position.

Referring more particularly to the drawings, reference numeral 2indicates generally the circular sleeve lift clamp of my invention. Theclamp is composed of two tapered or coniform split ring halves 4 and 6which are pivotally jointed at their ends. The pivotal connectionbetween the two split ring halves may be achieved by providing abifurcated member 8 on each end of the ring half 6 and a tongue member10 at each end of the ring half 4 which is adapted to fit between thebifurcations of the member 8. The bifurcated members 8 and the tonguemembers It) are each provided with matched openings, not numbered,therethrough which are located a slight distance from the bottom edge ofthe clamp. When the tongues 10 are fitted into the members 8, thematched holes are in alignment to receive a hinge pin 12 which holds thering halves in pivotal connection. Each of the hinge pins 12 may besecured by means of a cotter pin 14.

As a result of the coniform construction of the split ring halves, theassembled clamp 2 is similar in shape to a section of a hollow cone witha small diameter opening 16 at the top and a relatively larger diameteropening 18 at the bottom. The hinge pins lie in a common plane slightlyabove the larger diameter opening 18. The diameter of the top opening 16is somewhat larger than the outside diameter of the tuyere W to behandled so as to allow easy passage of the tuyere in and out of theclamp.

To assure a non-slipping grip, blades or grips 20 may be welded orotherwise attached to the inner periphery of the assembled clampcoincident with the smaller diameter opening 16.

An inverted L-shaped handle 22 is attached to the outer surface of themid-section of each of the ring halves 4 and 6 for pivoting the same andlifting the clamp. Each of the handles 22 has a relatively long portion24 extending in the direction opposite to the larger diameter opening 18angularly away therefrom and a short portion 26 extending outwardlysubstantially normal to the portion 24.

In operation, the workman standing above on the bottom plate beingrepaired holds the gripper loosely by the handles 22 with the taperedopening aimed to receive the tuyere as it is pushed up through theopening in the plate. When the tuyere has passed a short distancethrough the clamp, the workman raises the handles 22 causing the gripperjaws to close and the knife-edge blades 2% to bite into the tuyere wall.Then lifting on the handles, the workman pulls the tuyere up until theshoulder thereof is tight in the socket of the opening. He then holdsthe tuyere in position by exerting a lifting force on the handles 22until the tuyere is secured from below. After the tuyere is fastened,the workman releases the device by relaxing the lift force, and with anoutward breaking movement of the handles, widens the opening between thejaws and lifts the device off.

The hinge pins 12, which connect the members 8 and 10, are carefullylocated so as to restrict the pivoting motion of the ring halves ineither direction as best shown in Figures 4 and 5. The members 8 and 10and pins 12 are positioned so as to restrict the amount the clamp mayopen so that the bottom of the clamp will not bind on the tuyere as itis being removed therefrom as shown in Figure 4. The pivoting motion ofthe ring halves in the other direction is also limited as shown inFigure 5 so that the tuyere may easily slide up into the clamp. If theclamp closed up beyond the limits shown in Fig ure 5, it would have tobe held rigidly by the handles to receive the tuyere. However, with thepivot point properly located on each side, merely resting the device atthe top of the tuyere, while holding it lightly by the handles 22 willcause it to go down over the tuyere, and then stopping the downwardmovement and exerting a slight lifting force will cause the blades 26 toengage the tuyere surface. Increasing the lifting force on the handles22 to elevate the tuyere causes the blades hinge pins 12 and the handles22, through which the vcr tical lifting force is applied, provides aconsiderable mechanical advantage when the resultant force istransferred to a horizontal grip at the blades. I have found that thegripping power increases in the ratio of about 5 times the lifting forceas the tuyere shoulder is pulled up tight in the socket with my device.In other words, if lifting the weight of the tuyere and the grippingtool required a force of pounds upward on each handle, the resultantsqueeze of the blades against the tuyere surface would be about 175pounds, sufficient to prevent slipping and consequent danger.

While one ernbmodiment of my invention has been shown and described itwill be apparent that other adaptations and modifications may be madewithout departing from the scope of the following claims.

I claim:

1. Apparatus for handling an elongated object comprising a pair of firstand second tapered split rings, means pivotally connecting said ringstogether at their ends to form a pivotal sleeve clamp, the taper of saidrings forming a relatively greater diameter opening at the lower end ofsaid clamp and a relatively smaller opening at the upper end, saidpivotally connecting means including a bracket having an inner wall ateach end of said first split ring, said brackets each having atransverse hole therethrough adjacent said larger diameter opening, atongue projecting angularly from each end of said second split ring andhaving a lower shoulder thereon, each of said tongues being slidinglyfitted into one of said brackets, each of said tongues having atransverse hole therethrough communicating with the holes in saidbrackets, a pin rotatably fitted through the bracket and tongue at eachend of said split rings to thereby pivotally connect the same together,the lower shoulder of each of said tongues cooperating with the innerwall of its respective bracket to prevent the lower end of said clampfrom closing on the elongated object as it is moved through the clamp,and a rigid handle attached to the outer surface of each split ring forpivoting the same.

The blades 23 2. Apparatus for handling a cylindrical elongated objectcomprising a pair of first and second tapered split rings, meanspivotally connecting said rings together at their ends to form a pivotalsleeve clamp, the taper of said rings forming a relatively greaterdiameter opening at the lower end of said clamp and a relatively smalleropening at the upper end, said pivotally connecting means including abracket having an inner wall at each end of said first split ring, saidbrackets each having a transverse hole thererhrough adjacent said largerdiameter opening, a tongue projecting angularly from each end of saidsecond split ring and having an upper shoulder thereon, each of saidtongues being slidingly fitted into one of said brackets, each of saidtongues having a transverse hole therethrough communicating with theholes in said brackets, a pin rotatably fitted through the bracket andtongue at each end of said split rings to thereby pivotally connect thesame together, the upper shoulder of each of said tongues cooperatingwith the inner wall of its respective bracket to prevent the upper endof said clamp from closing substantially beyond the diameter of saidelongated object so as to facilitate lowering of the clamp onto theelongated object and to prevent excessive indentation of the elongatedobject by the clamp, and a rigid handle attached to the outer surface ofeach split ring for pivoting the same.

3. Apparatus for handling a cylindrical elongated object comprising apair of first and second tapered split rings, means pivotally connectingsaid rings together at their ends to form a pivotal sleeve clamp, thetaper of said rings forming a relatively greater diameter at the lowerend of said clamp and a relatively smaller opening at the upper end,said pivotally connecting means including a bracket having an inner wallat each end of said first split ring, said brackets each having atransverse hole therethrough adjacent said larger diameter opening atongue projecting angularly from each end of said second split ring andhaving an upper and lower shoulder thereon, each of said tongues beingslidingly fitted into one of said brackets, each of said tongues havinga transverse hole therethrough communicating with the holes in saidbrackets, 21 pin rotatably fitted through the bracket and tongue at eachend of said split rings to thereby pivotally connect the same together,the upper shoulder of each of said tongues cooperating with the innerwall of its respective bracket to prevent the upper end of said clampfrom closing substantially beyond the diameter of said elongated objectso as to facilitate lowering of the clamp onto the elongated object andto prexent excessive indentation of the elongated object by the clamp,and the lower shoulder of each of said tongues cooperating with theinner wall of its respective bracket to prevent the lower end of saidclamp from closing on the elongated object as it is moved through theclamp, and a rigid handle attached to the outer surface of each splitring for pivoting the same.

4. Apparatus for handling a cylindrical elongated ob ject as defined byclaim 3 including gripping means dis posed on the inner periphery ofsaid clamp around the smaller diameter thereof.

References Cited in the file of this patent UNITED STATES PATENTS148,148 Smith Mar. 3, 1874 189,688 Bogert et al Apr. 17, 1877 1,642,832Traves Sept. 20, 1927 1,720,500 Watrous July 9, 1929 2,218,845 KigginsOct. 22, 1940

